Pulp.



G. W. ROBERTS.

PULP.

APPLIOATIOH FILED APlLfi, 1907.

Patented Apr.5, 1910.

WITNESSES UNITED STATES PATENT OFFICE.

CHARLES W. ROBERTS, OF LOOKPORT, NEW YORK, ASSIGNOR TO FOREST LA NJT & MILL (10., OF TUPPEB LAKE, NEW YORK, A CORPORATION OF NEW YORK.

PULP.

Specification of Letters Patent.

Patented Apr. 5, 1910.

To all whomylt may concern:

Be it known that I, CHARLES W. Rename, a citizen of the United States, residing at 'Lockport, New York, have invented a certain new and useful Process for Manufacturing Pulp, of which the following is a s ecification.

eretofore in the manufacture of paperboard from spruce and similar woods, the logs were first stripped of bark and these shavings or rossings were used for fuel or in some other way whereby the rossin'gs were disposed of, they being considered in the nature of waste material. As'it was impgrtant that the spruce logs subsequently to treated for the purpose of making pulp out of them, were required to be completely clear of all bark, it followed that these rossings consisted of a very considerable pro ortion of wood in addition to the outer sur ace of the bark, the, roportion in many cases being 70% wood fiber and more or less powdery bark. I for years tried to make use of these shavings for the purpose of making pulp therefrom but their nature and consistency defied all m efi'orts, they being hard and thin and tliere being no known way of separating or disintegrating their fibers so as to make them useful for the purposes of wood pulp. I have now,

after many experiments and much thought,

- discovered a way of using these rossings for the purpose of makin pultpxin all respects,so or as I can see, equal an excellent wood 6 pulp made from the spruce logs according to the old process and in some respects, su erior thereto. The rocess of treat' t ese rossings, which have dei ised is applicable to other fiber, however,

and I do not in my broader claimsdesire to'restrict myself to the use of the process in connection with the rossings.

The object of my invention is, therefore, to produce a wood pulp for use in the manufacture of paper or pa erboard with greater economy than hereto ore, and the invention consists more particularly in the process of manufacture of such pulp as hereinafter described and claimed.

In the accompanying, drawin s I have shown a plan of a mill m which t 0 process devised by me may be efliciently carried out.

Before explaining this drawmgin detail, I shall describe the nature of my invention. I first take the and hard shavings, consisting as above stated of for instance, 70% fiber and 30% bark, to ether with the refuse sawdust that comes em thewood .ulp mill, and run them through a cutter. his c'utter reduces the entire mass of material into short lengths. Except for the dust, I prefer to arrange the cutter so that the bulk of the rossings is reduced to lengths not less than inch lon and not more than three inches long. W' on the rossings are in this condition, they are placed into a boiler ahd cooked, preferably under a pressure of not less than 20 ounds and not more than 120 pounds TlllS cooking is continued until the shavings are thoroughly softened, after which the cooker is dum ed into a storage vat beneath the same. rom this storage vat the material is passed through, what I call for want of a better term, a compressor. The construction of the compressor is immaterial. The use of this compressor at this particular point. in the operation is of the essence of my invention. The work it must accomplish is the following: The softened shavings from the cooker must be compressed under a high pressure and simultaneously with such compression must be allowed a motion of all their constituents with reference to each other. In other words, there must be a compound motion whereby, as the compression roceeds, the various individual shavings will rub against the adjacent shavings so that, as the operation proceeds, the fibers comprising the individual shavings will thoroughlv and completely rub themselves apart. n this way not on] body 0 the shavings (in the machine as I adjust it to the extent of about 80% of the water) but the fibers as they emerge from the machine are almost com lete y individualized. An ordinar grin ing machine is unable to do this wor r because of the exceedingly high pressure which is the prerequisite of t is step in the process. I prefer to use for this purpose a machine having a stron outer casing tapering toward one end, w ich contains a solid tapering core spirally grooved, the spiral groove diminish ing in diameter as the orifice of the machine is moisture driven out from the affords, I obtain the exact result aimed at. The stock as it emerges from this com pressor passes through a small die having a discharge opening for the completely treated stock. he action ofthis compressor, acting as it does under an enormous pressure on the stock,-brings the stock into a condition where the fibers readily separate and from this point on they are easily made flexible and readily take on the felting quality so much desired in the manufacture of paperboard or the like.

The particular compressor which I preferably use is a well known machine and is used for other purposes in the paper makin arts so that its detailed construction nee not be described. After the stock has been compressed and is in a condition for the rca through the usual paper' inakin process; that is, it passes' through'a grin er which reduces the stock to almost its final condi tion. Large quantities of the compressed softened stock can be added to the grinding machine because, being dry, it occupies very much less physical space than is thecase in the rocess now in use. Fresh water is adde to the grinding machine in quantities suflicient to proceed with the further process.

From the grinder the stock is passed to a large storage vat continuously agitated so as not to allow the fiber to settle. From this storage vat the stock is withdrawn as desired through a distributing vat into a refining engine, after which it is in condition to go on to the wet machine. By using the compressor at the point where I use it, I not only make it possible to use the rossings which have heretofore always been-useless but I also enable thcgrinders and rclincrs (in case of other stock as well as of shavings) to do far more work at far greater speed. .Vherc now, 'for instance, the capacity of a )ulp mill is limited by the number of rcning engines, the introduction of a coinpressor at the point of the operation selected by me makes it possible for the refiners and the grinder to do at least three'times the amount of work done by these machines under ordinary circumstances. In the mill illustrated in the drawings, for instance, if it were desired to treble the capacity, it would be necessary to introduce at least six new refining engines. By the introduction ol the compressor between the cooker and the grinder, however, the present size and urran cmcnt of the mill is sullicient to do this vastly augmented work without the addition of any new engines or the employment of more workmen.

In the drawing A desi mates the cutter; C the cooker; D t it: storage vat for the cooked shavings; E the compressor; the grinder; G the storage y separation of its fibers, it is passed' wood then simultaneous vat for the ground shavings; H the distributing vat; ,I the refiners; K the final stora e vat and L the wet machine. From t e above description it will be noticed that m invention differs from the process of making pulp chiefly in the introuction at that stage of the process after. the stock has been cooked of a step whereby the material is thoroughly softened, dried and compressed and to a certain extent disintegrated into its component fibers. in the case of rossings, the bark gives the fiber a rich brown tint. The fiber that is, the wood pill), produced from these rossings-is excec ingly strong and tough and is in all res ects as diluent and useful as the fiber which has heretofore been produced from the spruce logs. It will be seen that by my invention I am enabled to make use of a paper mill product which has gone to waste to the extent of thousands of tons in the past and that the invention will enable me to erect and maintain many pulp mills and to give employment to a large force of workmen where formerly there was absolutely no industry whatsoever.

Havin nowpartic'ularlv described the nature 0 this invention, I claim:

1. The improvement in the process of making wood pulp which comprises sub ecting the cut and cooked stoc to attrition under great compression then' grinding the stock for the first time, substantially as described.

2. The process of making paper pulp which comprises cooking the stock, sub e cting it to enormous ressure and attrition obtained by compressing it iinall directions simultaneously, then grinding and refining the compressed product substantially as described.

The process of making wood pulp which comprises cookin the disintegrated compressing and drying-it while subjecting it to attrition by the application of enormous pressure in all directions simultaneously and reducing the compressed stock into fibers substantially as described.

4.. The process of making wood pulp which comprises cooking the stock then subjecting it to enormous pressurean all directions simultaneously whilecausing the ndividual particles to rub against and d sintegrate one another and subs nently grinding the compressed mass, sustantially as described.

The process of makin wood pulp from shavings or rossings whici com )rises cutting the same into lengths of su stantially uniform size, cooking the same, then coinrcssing the individual particles under the influence of attrition intoa homogeneous mass of loosened, softened wood cells, and

finally grinding the softened stock, substantially as described.

6. The process of making paper pulp which comprises cooking the stock, subjccting it to enormous pressure by prcssingit in all directions simultaneously so as to ex ml the water and at the same time induce ilieicnt attrition to loosen the individual fibers, then adding water to the resulting product While grinding it and disintegrating such product in the presence of a Large amount of water, substantially as described.

7. The process of making paper pulp which comprises subjecting the stock to enormous pressure and attrition obtained by l ctunpressing it in all directions simultaneously, then pressed product substantially as described. 8. The process of making wood pulp which comprises simultaneously compress ing and drying the disintegrated wood, while subjecting it to attrition by the application of enormous pressure in all directions siniultaneousl and reducin the compressed stock into fibers snbstantia ly as described.

winding and refining the com- 9. The process of making wood pulp which comprises subjecting the stock to enormous pressure in all directions simultaneously while causing the individual particles to rub against and disintegrate one another and subsequently grinding the compressed mass, substantially as described.

10. The process of making paper pulp which comprises subjecting the stock to enormous pressure by pressing it in all directions Sill'lllllfllltOllHlV so as to expel the water and at the same time induce sullicient attrition to loosen the individual fibers, then adding water to the resulting product; while grinding it and disintegrating such product it] the presence of a large amount ot water, substantially as described.

In witness whereof I have hereunto set my hand in the presence of two subscribing witnesses.

cumulus W. ROBERTS. \Vitnesses:

\V. JOHN HINCKEY, J. L. SHELDON, Jr. 

